Hide settings/apps unless apps:true is in config.js

fixes #3031

- Adds an initializer for passing config to the frontend, it's not pretty but it works
- Forwards the apps route and hides the apps menu item if apps:true is not present in config.js

ghost/admin/controllers/settings.js

@@ -0,0 +1,5 @@
+var SettingsController = Ember.Controller.extend({
+    showApps: Ember.computed.bool('config.apps')
+});
+
+export default SettingsController;

ghost/admin/initializers/ghost-config.js

@@ -0,0 +1,12 @@
+var ConfigInitializer = {
+    name: 'config',
+
+    initialize: function (container, application) {
+        application.register('ghost:config', application.get('config'), {instantiate: false});
+
+        application.inject('route', 'config', 'ghost:config');
+        application.inject('controller', 'config', 'ghost:config');
+    }
+};
+
+export default ConfigInitializer;

ghost/admin/routes/settings/apps.js

@@ -1,6 +1,11 @@
 import AuthenticatedRoute from 'ghost/routes/authenticated';
 
 var AppsRoute = AuthenticatedRoute.extend({
+    beforeModel: function () {
+        if (!this.get('config.apps')) {
+            this.transitionTo('settings.general');
+        }
+    },
     model: function () {
         return this.store.find('app');
     }

ghost/admin/templates/settings.hbs

@@ -13,9 +13,11 @@
                     {{#link-to "settings.user"}}User{{/link-to}}
                 {{/view}}
 
+                {{#if showApps}}
                     {{#view "item-view" tagName="li" class="apps"}}
                         {{#link-to "settings.apps"}}Apps{{/link-to}}
                     {{/view}}
+                {{/if}}
             </ul>
         </nav>
     </aside>